The invention is an interior lighting system for vehicles that employs a multistage rotary switch with a shaft that is more or less perpendicular to the front of the lighting unit and that has a cam that activates spring contacts with free ends, each of which can be tensioned against an associated fixed contact to establish a connection.
The rotary switches used to illuminate the passenger area in a vehicle can be activated directly by hand in one stage and indirectly in another through a subsidiary switch in the doorway. These two stages are attained with a cam that is attached to the shaft and that acts on two spring contacts.
Contemporary interior light fixtures are often mounted in the roof structure of the vehicle above a point between the driver and the front-seat passenger, from where the fixtures illuminate the passenger area well. Since overall illumination, which may dazzle the driver, is not required for all purposes, it is practical for the lighting system to include a reading state in which the illumination is focused on the front-seat passenger area. The disadvantage of lighting systems that employ a two-stage rotary switch and involve a reading state is that the lighting fixture requires an additional switch for the reading light.
The invention is intended as a simple and easy to manufacture rotary switch with at least three stages for use in lighting systems of the type described above.